If you only have single-phase 220 V electricity at home, in a small workshop, a garden or on a farm, the motor you can use is a single-phase motor. When you ask for prices, even two single-phase motors of the same power can differ. In this article we explain what determines the price of a single-phase motor, the mistakes people make when asking for a price on the phone, and when a three-phase motor is more economical.

1. Power (kW)
Power is the biggest price factor. HEM Motor’s single-phase range covers 0.18 kW to 5.5 kW. As power increases, the frame, copper winding and lamination stack grow, and so does the price.
Buying an oversized motor raises the price and also draws more current on a single-phase line at start-up. Use the power shown on your old motor’s nameplate.
2. Speed
Single-phase motors are made in 3000, 1500, 1000 and 750 rpm options. At the same power, the lower the speed, the larger the frame; that is why a low-speed motor costs more. Pumps and fans usually use 3000 or 1500 rpm, mixers and geared machines 1000 or 750 rpm.
3. Capacitor arrangement and starting power
A single-phase motor cannot start turning on its own; a capacitor provides the start. The capacitor arrangement also affects the price:
- Single (run) capacitor motor: Suitable for light-start jobs such as fans, extractors and pumps that start unloaded. More affordable.
- Start + run capacitor motor: Needed for compressors, pumps that start under load and machines that start loaded. More expensive because it has an extra capacitor and switching element.
Using a light-start motor on a hard-start job can cause the motor to fail to start and the winding to overheat and burn. Choose the motor that suits the job, not the cheapest one.

4. Mounting type
How the motor attaches to the machine also changes the price. The foot-mounted (B3) motor is the most common type. Flange (B5, B14) or foot-and-flange (B35) motors need an extra end shield and machining, so the price differs. If it replaces an old motor, the mounting type and shaft size must be the same.












